Tuesday, June 19, 2012

Pre-Columbian Humans Had Little Effect On Amazon Rainforest

June 15, 2012
Source: RedOrbit

Crystal McMichael and other scientists collect soils in the Peruvian Amazon. Credit: Crystal McMichael
Early inhabitants of the Amazon River Basin had little long-term impact on the forests in the area, overturning the notion that the region was a cultural parkland during pre-Columbian times, claims a new study published in the June 15 edition of the journal Science.

The discovery comes after a team of researchers hailing from the Florida Institute of Technology (FIT), the Smithsonian Institution, Wake Forest University and the University of Florida (UF) conducted the first landscape-scale sampling of central and western Amazonia, according to a Thursday FIT press release.

They discovered that the earliest inhabitants spent most of their time near lakes and rivers, and had such little affect on the areas further inland that it seemed as if they could have been tip-toeing from one body of water to another, they added.

“The research team, led by Florida Tech’s Crystal McMichael and Mark Bush, retrieved 247 soil cores from 55 locations throughout the central and western Amazon, sampling sites that were likely disturbed by humans, like river banks and areas known from archeological evidence to have been occupied by people,” the university explained.

“They also collected cores farther away from rivers, where human impacts were unknown and used markers in the cores to track the histories of fire, vegetation and human alterations of the soil. The eastern Amazon has already been studied in detail,” they added. “McMichael, Bush, and their colleagues conclude that people in the central and western Amazon generally lived in small groups, with larger populations on some rivers.”

Their findings are important, as they shed new light on how the Amazonia — one of the world’s most biologically diverse areas — was impacted by humans during its earliest days. That knowledge can help experts learn more about the ecological processes of tropical rainforests, and could aid ongoing conservation efforts, according to FIT.

“Drawing on questionable assumptions, some scholars argue that modern Amazonian biodiversity is more a result of widespread, intensive prehistoric human occupation of the forests than of natural evolutionary and ecological processes,” Dolores R. Piperno, co-author of the study as well as a senior scientist at the Smithsonian Tropical Research Institute, said in a separate statement.

“Climatologists who accept the manufactured landscapes idea may incorporate wholesale prehistoric Amazonian deforestation, widespread fires and carbon emissions into their models of what caused past shifts in atmospheric carbon dioxide and methane levels. But we need much more evidence from Amazonia before anything like that can be assumed,” she added.
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